B. P.  Machado*, D. Alves, P. Guedes de Pinho, T. Hogg and A. C. Silva Ferreira

Escola Superior de Biotecnologia, Universidade Católica Portuguesa
Rua Dr. António Bernardino de Almeida. 4200-072 Porto, Portugal.

Twenty five wines from four regions (Estremadura, Douro, Alentejo e Dão) of Portugal, plus 10 Porto wines (Fortified wines) both 100% Touriga Nacional and 100% Tinta Roriz Wines, were used to investigate the effect of “terroir” and wine production technique on the “Typical character of TN wines” using chemical and sensory analysis.

The sensory characteristics of the wines were profiled using descriptive analysis (QDA). Eleven trained judges evaluated 16 aroma (Bergamot, Violet/Floral, Critic, Balsamic, Veggie, Herbaceous, Caramel, Butter, Spicy, Dried Fruit, Berry Fruit, Tree Fruit Tropical Fruit, Oak, Nutty and Chemical/alcohol) sensory attributes.

Data were analyzed using analysis of variance, and principle component analysis (PCA). A PCA of all wines, using the 16 sensory descriptors, indicated that 56,7% of the variability could be explained in the first two dimensions. Data reveals that Port wines had more balsamic, caramel and dried fruit aromas and lowest bergamot, berry fruit, tropic fruit and tree fruit compared the others table wines.

The panel distinguishes Tinta Roriz from the other Touriga Nacional wines, scoring the first higher in herbaceous and veggie aromas. Nevertheless no differences between regions can be observed when comparing Touriga National table wines.

By gas chromatography-olfactometry analysis three odorant zones (OZ) related to these descriptors in the Touriga Nacional wines could be determined as: “Bergamot-Like”; “Citric”; “Tropical fruits”. By AEDA it was confirmed their importance and it was verified that it discriminates from other varietals. The “Bergamot-Like”; “Citric”; were related to the presence of Linalol (in agreement with the odour of both isomers of these tepenol) and with linalyl acetate.  A similarity test was performed with a non TN wine added with linalool alone or in combinations. The highest similarity value was observed when linalool (SV=5.9) is added. In fact, results obtained from the analysis of several red wines from different varieties show that terpenols are present in higher amounts in wines coming from TN variety which prove that these compounds are the clue of the varietal aroma of TN wines.